Critical factors in healing acute wounds

Even dermatologists might be surprised by what really matters and what doesn’t when it comes to optimal wound healing. Things many doctors were taught in residencies, such as telling patients to avoid getting their sutures wet, doesn’t seem to make a difference. And one of the biggest wound healing stressors is stress, according to Robert S Kirsner, M.D., Ph.D., chairman and professor of dermatology and cutaneous surgery, and professor of epidemiology and public health director, University of Miami Hospital Wound Center, University of Miami Miller School of Medicine, Miami, Fla.

Dr. Kirsner reviewed what has panned out in the literature to positively impact wound healing, as well as what might be a waste of time and money, when he presented on the topic of acute wound healing in January 2016 at the Maui Derm 2016 meeting in Maui, Hawaii.

“In essence, stress matters, smoking matters, pre-treatment with retinoids matters, and age affects the perfect scar. Other things that matter are suture choice, occlusion and postoperative wound tension,” Dr. Kirsner says. “Things that may not matter include wound eversion; getting sutures wet; using antimicrobial versus other ointments, or using any ointments under occlusive dressing; and even the epidermal closure may not be important if you close the deep wound appropriately.”

Stress impedes wound healing by as much as 40%, according Dr. Kirsner.

“The mechanism is pretty well worked out. A physiologic or psychologic stressor causes the pituitary gland to release adrenocorticotropic hormone, which stimulates the adrenal gland to release steroids and catecholamines. Specifically, with regard to steroids, this causes a reduction in the number of circulating inflammatory cells and production of pro-healing cytokines,” Dr. Kirsner says.

The clinician, therefore, should aim to create a stress-free environment for patients with wounds, according to Dr. Kirsner.

“If somebody is really stressed or is having a stressful event in their lives and is having an elective procedure, perhaps postpone the procedure until the stress has passed,” he says. “Importantly, pain can induce stress, so just by reducing pain during surgery and postoperatively, we may speed wound healing.”

Smoking matters

Dermatologists should encourage patients to stop smoking a month or more before surgery to improve wound healing.

Some say the damages from smoking can’t be reversed, but study results disagree, according to Dr. Kirsner.

“It turns out, there’s a fair bit of data that suggests smoking causes problematic healing, not only in the skin but in the bones and in the cornea. And if a person stops smoking for about a month, that will restore some of their inflammatory cellular function, reducing risk of infection. So, even stopping smoking for a relatively short time before surgery can be beneficial,” Dr. Kirsner says.

Pretreating with tretinoin matters (and hair reduction might matter)

Data going back three decades suggests that by applying topical tretinoin nightly for a month prior to surgery, patients’ wounds heal faster, compared to placebo cream. Dermatologists should consider the approach when doing different types of wounding procedures, like chemical peels and dermabrasion, according to Dr. Kirsner.

“Experimentally, people have been doing other things to speed healing prior to creating a wound. They’ve plucked or shaved the hair to stimulate follicular stem cells. They’ve waxed the hair. And at least in animal models, this seems to speed healing,” he says.

Age matters

Age matters, as does preparing patients for age-related wound healing challenges.

The culprit seems to be estrogen, in men and women. Researchers have shown that by giving an elderly patient hormone replacement therapy, one can shift the patient from an older person’s healing phenotype (slow healing with less scarring), to a younger person’s healing phenotype (faster healing, more scarring), he says.

“The most important tip there is to understand expectations and, in theory, if you really were interested in the cosmetic effect on the patient, perhaps, if they were on hormone replacement, you might want to stop it during the procedure. If you’re worried about slow healing in a patient, you may want to add hormone replacement therapy. But that’s experimental,” Dr. Kirsner says.

One caveat: Estrogen’s effect may depend on the type of wound.

“We do know the deeper wounds scar more, so, maybe, the estrogen has a more profound effect on the fibroblasts deep in the dermis, as opposed to superficially,” he says.

Suture type matters

The type of sutures dermatologists use could impact patients’ wound healing.

Sutures coated with antiseptic seem to reduce infection, at least in the oral mucosa. They also reduce bacterial counts and pain, according to the dermatologist. Some studies suggest sutures made from novel materials, such as chiton, may accelerate wound healing.

Occlusion matters

Covering a wound with an occlusive dressing speeds wound healing, especially for partial thickness wounds. Other benefits of occlusive dressing are improved cosmetic results and less pain. Studies have not shown an increased infection risk with occlusion, according to Dr. Kirsner.

The benefits of using an occlusive dressing on wounds versus no occlusive dressing seems to be mediated through downregulation of inflammatory cytokines and certain keratin proteins, he says.

Postop wound tension matters

Researchers at Stanford developed a dressing, called Embrace (Neodyne Sciences), which reduces the tension—the pulling forces away from the wound.

“Normally, when you suture a wound together, there are forces that pull it together that make the scar wider. This is a special dressing that prevents that pulling of the wound …” Dr. Kirsner says. “They studied it in animal models and in human models with abdominoplasty and breast scar reduction—all finding that if you use this dressing you have less wide scars and more cosmetically acceptable scars.”

Some have tried using Botox [Allergan] to reduce tension across the wound, he says.

“There are some animal models to suggest Botox can improve the scars by reducing wound tension,” Dr. Kirsner says.

Dermatologists and other doctors might instruct patients not to get their sutures wet. But researchers have shown that people who get their sutures wet with normal bathing have no increased infection risk, according to Dr. Kirsner.

Cutaneous sutures don’t matter

The general thinking in medicine is that cutaneous suturing may lead to better cosmetic results. But researchers, according to Dr. Kirsner, have found no significant difference in cosmetic results after closing with deep with buried sutures, whether Steri-Strips (3M) or cutaneous sutures were used. They’ve also studied (and found no differences) when after placing deep buried sutures, whether Steri Strips versus not closing the wound on the epidermis at all.

“So, when you close the wound, you may not need to put superficial stitches in at all, but it is important to apply an occlusive dressing,” Dr. Kirsner says.

Everting the wound? Matters not.

“People ask: What about everting the wound, and do you need cutaneous stitches to evert the wound? One study showed no difference in wound eversion versus no wound eversion at three months follow up,” Dr. Kirsner says. “It’s something that we’re taught, but it may not be important to evert the wound at the time of wound closure.”

Ointment beneath occlusive dressing doesn’t matter

Some providers put an ointment underneath the occlusive dressing—a practice researchers have found makes no difference in wound healing.

“…it made no difference with regard to infection if you put an antibiotic ointment, no ointment or a Vaseline ointment as long as you put an occlusive dressing on. After that you don’t need to add additional occlusion with an ointment,” Dr. Kirsner says.

Keeping up with the latest findings in wound care matters, according to Dr. Kirsner.

“I think that in order to make sure that we’re giving the state-of-the-art or standard of care to our patients, we want to keep abreast of the literature,” he says. “We shouldn’t only rely on what we were taught in residency and what our teachers did, but rather base on decisions from well done clinical trials.”